Outcomes of gestation length in relation to farrowing performance in sows and daily weight gain and metabolic profiles in piglets

The objectiveof this study was toevaluate uterineactivity at farrowing insows with differentgestation lengths (GL),anditseffectonthemetabolicprofile,bloodgasesanddailyweightgainofneonatepiglets.Theexperimentcovereda period of 25 weeks and involved 200 Yorkshire-Landrace sows. The animals were assigned to four groups of 50 sows each and distributed according to GL, as follows: GL1: 107-109 days; GL2: 110-113 days; GL3: 114-116 days; GL4: 117-119days.Theproductiveindicatorsofthesowswererecorded,aswerethesurvivaloutcomesoftheneonatalpigs.Fetal cardiac frequency and both intensity and frequency of myometrial contractions were monitored using a Corometrics Fetal monitor.Thebloodgases,electrolytesandglucoselevelsoftheneonateswereobtainedbymeansofanautomaticbloodgas and electrolyte analyser. The GL groups GL1 and GL2 had more prolonged births (>226.26 4.95 min) regardless of litter size(P <0.05).Ofthefourgroups,GL1presentedthelongestduration(P <0.05)oftheexpulsionphase(P <0.05),thehighest numberofuterinecontractions(P <0.05),andthehighestandlowestnumberofintra-partumdeaths(P <0.05)andlivebirths, respectively. The live birth piglets in this group had both the lowest birthweights (P < 0.05) and the highest incidences of hypercapnia, hyperlactatemia and hypercalcaemia (P < 0.05), which later resulted in lower rates of daily weight gain (P < 0.05). In conclusion, premature births increase the number of intra-partum deaths and result in lower birthweights, the presence of apnoea, and severe metabolic alterations in piglets.